It is well known in the art that the ordinary engine driven mower is unable to pass close enough to a raised obstruction to cut the grass all the way up to its edge, and it is also well known that the ordinary mower is not equipped for trimming and edging purposes. Accordingly, separate machines are sold for these two purposes, the same machine often performing either edging or trimming depending on whether the shaft of the machine is held in a horizontal or a vertical position during use.
Numerous attempts have been made to provide an attachment for present-type mowers to accomplish these trimming and edging functions, for instance as shown in U.S. Pat. No. 3,531,922 to Hensen. This patent shows both edging and trimming means, but no provision is made for moving the edger away when only trimming is desired.
U.S. Pat. No. 2,663,137 to Asbury; U.S. Pat. No. 3,192,693 to Bergeson; U.S. Pat. No. 3,812,917 to Strate; U.S. Pat. No. 3,871,160 to Hooper and U.S. Pat. No. 3,407,579 to Decker, all show trimming or edging attachments for a lawn mower, but both types of attachments also combined in the same device. Some of these patents show various and sundry means for tightening and loosening a drive belt so that the attachment can be disabled when its function is not needed, for instance U.S. Pat. No. 3,407,579 having a movable idler pulley pressing against the drive belt to tighten it. Additionally, U.S. Pat. No. 2,663,137 shows an edger of the type using flexible flail members instead of rigid blades.